The invention relates to an electronic unit as claimed in the precharacterizing clause of patent claim 1.
An electronic unit such as this is disclosed, for example, in U.S. Pat. No. 6,068,180. This patent specification describes how contact is made between a semiconductor component and a mounting board, which has conductor tracks embedded in plastic. The ends of the conductor tracks are equipped with contact surfaces for making contact with the connections of the semiconductor component. One disadvantage of this arrangement is that, in order to check the functioning of the electronic unit by means of a current or voltage measurement apparatus, either the same contact surfaces which were previously used to make contact with the semiconductor component must be used to make contact with the current or voltage sensors of the measurement apparatus, or else additional contact surfaces must be provided on the mounting board, which are provided exclusively for making contact with the current or voltage sensors of the measurement apparatus.
The object of the invention is to provide an electronic unit of this generic type in which the capability to connect the current or voltage sensors of a measurement apparatus is improved.
According to the invention, this subject is achieved by the characterizing features of patent claim 1.
Particularly advantageous embodiments of the invention are described in the dependent claims.
The electronic components of the electronic unit according to the invention are arranged on a mounting board, which has metal webs embedded in an electrically insulating material. The metal webs, which are normally used as conductor tracks between the electronic components, have a first side which is in the form of a contact surface for making contact with the electronic components, and a second side facing away from it. According to the invention, cutouts are arranged in the electrically insulating material, via which the second side of each metal web is accessible for a voltage or current measurement apparatus. The second side of the metal webs, which are connected to the electronic components to be tested by a measurement apparatus, is used as a contact surface for the current or voltage sensors of the measurement apparatus. It is thus possible to use the same metal webs which were used to make contact with the electronic components to make contact with the current or voltage sensors of the measurement apparatus as well without, in the process, having to subject the contacts of the electronic components to the risk of damage. Furthermore, no additional contact surfaces need be provided on the mounting plate for the current or voltage sensors of the measurement apparatus, either.
The electronic unit according to the invention is advantageously designed such that the mounting board has a top face from which the first side, which is in the form of a contact surface, of the metal webs is accessible and on which the electronic components are arranged, and has a lower face, which faces away from the top face and is provided with the cutouts. The current or voltage sensors of the measurement apparatus thus produce the contact, via the lower face of the mounting board, with the electronic components which are to be tested and are mounted on the top face, preferably using SMD technology (SMD is an abbreviation for Surface Mounted Device). In consequence, the design of the current or voltage sensors of the measurement apparatus need not take any account of the physical height of the electronic components.